The present invention relates to digital signal processing, and more particularly to image stabilization methods and imaging devices with electronic stabilization.
Image stabilization (IS) is the task of eliminating jitter from video sequences captured by handheld cameras. Jitter is typically due to the undesired shake of the hand during video recording, and becomes a more severe problem when higher zoom ratios are used. Eliminating jitter from video sequences has been an increasingly important problem for consumer digital cameras and camera phones. There are a few different approaches to the solution of the image stabilization problem. One particular approach is to use digital image processing techniques to eliminate jitter. This approach is generally called “digital image stabilization” (DIS).
A typical digital image stabilization method can be summarized as follows:    Step 1: Motion vector computation: Compute a number of candidate motion vectors between two frames by finding the correlations between blocks of pixels.    Step 2: Global motion vector determination: Process the candidate motion vectors from step 1 using a number of heuristics to find the global jitter motion between the two frames.    Step 3: Motion compensation: Compensate for the estimated jitter motion by digitally shifting the output image in the reverse direction of the motion.            For examples, see U.S. Pat. Nos. 5,748,231, 5,563,652, and 6,628,711.        